You tried on both USB ports? I mean the normal USB on the keyboard & the micro-USB on the tablet itself.

I don't have the keyboard. I tried using the micro USB on the tablet itself directly or indirectly (with usb hub attach to it)

I am sorry .... I got confused with the Switch 10 that comes with the keyboard. I have already sold my Iconia W4 & bought the Switch 10 as a replacement.

Nevermind, thank you anyway.

I think it is processor or bios problem because if I place "bootia32.efi" inside "/efi/boot/" folder, i can choose to boot from the usb flash drive but it comes out with an error "this 64-bit application couldn't load because your pc doesn't have a 64-bit processor ...".

Fyi, I'm trying to install windows 10 64-bit on the tablet because i found that there is an "windows 10 64-bit" option to choose when i try to look for latest software / bios update from "http://www.acer.com.my/ac/en/MY/content/drivers".
Lenovo website also provide windows 10 drivers for miix 2 8 which have similar specs (same processor) with w4.

you cannot just to clean install per see. You need to first upgrade to tag your windows 8 serial key to Windows 10. Once that is done auto activated - ensure that you go online to communicate to MS servers.

How did you create your bootable USB drive? If you have not done so from Microsoft's website, do so:

http://www.microsoft.com/en-us/software-download/windows10

Select your version download. Once download has complete, it will ask you if you want to create a USB bootable drive or ISO file to burn to disk.

I already running windows 10 (32-bit).
After upgraded to windows 10, I try to use Rufus and diskpart to create 64-bit bootable usb disk, but it fails to boot.

After upgraded to windows 10, I found that the GPS is not working. Any idea?

If you install Windows 32-bit home, it'll automatically activate with OEM preinstalled keys in your tablet.

Windows 64-bit won't work so far. Even there's still no official drivers for the Win10 32bit. Still works with Win8 drivers 1.16.

Just sent my tablet in for warranty. Even though I havent use it in months, it started going crazy on me. Both bottom corners not reacting to touches.